Littlebeezy
Member
I'm growing in pots and soil. Read lots of stuff about 15/20% runoff. When I water I just water until I see the pot start to drain/runoff. Should I be giving them more water?
15/20% of what?
15/20% of what?
Question on runoff?
- Thread starter Littlebeezy
- Start date
orbo
Well-Known Member
Yes. You should be giving more. I have my best results growing in 5 gal container. 5 gal container will take 1 gallon of water and about 3 cups of it will pass completely thru out the bottom. 12 cups (1 gal) - 3 cups = 9 cups. 9/12=.75 meaning 75% of the water stayed in the pot and 25% run off.
The runoff is good for several reasons. Helps to wash away excess salt and help prevent salt buildup. You should also be checking your PPMs in the runoff and if you'd like to trend your pH coming out you can do that too. This will give you an idea about your soil's pH. example - if you put 6.5 water in and get 6.2 water out each and every watering..then its safe to assume your soil pH is a little low and likewise 6.5 with 6.8 means it a little high. There is some value to the pH trending data, not much but since your checking PPMs anyway......
The runoff is good for several reasons. Helps to wash away excess salt and help prevent salt buildup. You should also be checking your PPMs in the runoff and if you'd like to trend your pH coming out you can do that too. This will give you an idea about your soil's pH. example - if you put 6.5 water in and get 6.2 water out each and every watering..then its safe to assume your soil pH is a little low and likewise 6.5 with 6.8 means it a little high. There is some value to the pH trending data, not much but since your checking PPMs anyway......
thewanderer718
Well-Known Member
Great advice.
Littlebeezy
Member
Thanks for the info. I just got a ph kit so I can test ph runoff.
Dr. Who
Well-Known Member
OMFG!
pH of the run off is simply the pH of the run off! It is the most inaccurate way to attempt to figure pH.....
When you water the pH of the soil will drop and as it dries back out it will rise back up to it's actual soil pH value.....Be sure to have enough liming agent in the soil to start. FF soils need extra to start = add 1/2 cup of Dolomite lime to every bag of FFOF or FFHF..
If using synthetics - pH ingoing to 6.7 and water......soils under 6.5 tend to have poor Ca, Mg and P uptake....keep that in mind.
You do NOT have to water to run off at all - depending on what and how much/often you feed...
I would really be edgy about watering that much and letting my roots sit in wet soil as long as it would take to dry that out.....The more often you water the more o2 gets to the roots and that is VERY important.
What nutrient do you use?
How much do you use?
How often do you water? Feed?
pH of the run off is simply the pH of the run off! It is the most inaccurate way to attempt to figure pH.....
When you water the pH of the soil will drop and as it dries back out it will rise back up to it's actual soil pH value.....Be sure to have enough liming agent in the soil to start. FF soils need extra to start = add 1/2 cup of Dolomite lime to every bag of FFOF or FFHF..
If using synthetics - pH ingoing to 6.7 and water......soils under 6.5 tend to have poor Ca, Mg and P uptake....keep that in mind.
You do NOT have to water to run off at all - depending on what and how much/often you feed...
I would really be edgy about watering that much and letting my roots sit in wet soil as long as it would take to dry that out.....The more often you water the more o2 gets to the roots and that is VERY important.
What nutrient do you use?
How much do you use?
How often do you water? Feed?
I like lots of runoff as insurance against salt buildup later in the grow. If you feed exactly what your plant needs, you don't need to worry about it. But,
1) typically you don't know if you're feeding what your plant needs until you learn what too much is. It's easier to do a "mini flush" with each feed and not worry about it.
2) If you do feed an amount (without runoff) that doesn't lead to buildup, that doesn't mean the plant is eating or prefers the exact balance of nutrients that is available. I like to overfeed a little and mini-flush a little (20% runoff) to "reset" the plate of nutrients in the soil, refreshing the balance. Think of it as the difference between "you can't have more until you finish what's on your plate" versus a fresh(er) plate each time (and not worrying about it because the nutrients are, hopefully, inexpensive.).
If you grew in a soil with nutrients amended into it, especially organic, you wouldn't do this. But, the more synthetic your nutrients, the more I like to push out some of the old and replace with new.
orbo
Well-Known Member
Maybe you didn't catch that last sentence.
"There is some value to the pH trending data, not much but since your checking PPMs anyway......"
Runoff ph (as a reflection of soil ph) is complicated. Scroll down this page about halfway and read about the NCSU Pour Through Method. If you understand the variables, you can mentally adjust your readings (how long the water sat in the container, how much fresh solution displaced the saturated/equalized solution).
For the soil and nutrients I use, I found runoff ppm to be a better indicator of the soil's ph. When it reaches 2000 I stop feeding, or do half-strength and 100% runoff. (2500 is where it shows as a deficiency, lockout, soil ph 5.2).
Consider getting the soil probe mentioned there. That's really handy to have when you need it. If you have a starting ph adjusted as described there, PPMs should be a reliable indicator of the ph (and you can probe the soil anytime, and see how the ph changes as the soil dries, etc.).
Note: If you have a ph tester using "drops," that's probably not going to work well. Colored liquids throw it off. A ph pen is better, but a lot of work to maintain/calibrate. A ph pen is handy if you're going to ph your nutrients, but if you don't use "calmag", you probably don't need to ph your nutrients. (I don't.). In which case, the soil probe is a better investment (IMO).
orbo
Well-Known Member
RARELY will a grower put 6.50 water in his/her pot and get 6.50 water out. And knowing which way the soil shifts the pH of the water in is useful information. If/when you see deficiency's that are either on the high end of the scale of the low end it gives your the knowledge to be able to accurately adjust your pH going in - to get more time in the zone on the scale you need - before the soil buffers the water. Water doesn't instantly buffer to the soils pH, it takes time.
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orbo
Well-Known Member
I will qualify this statement with - knowing runoff pH it is useful when things are way out of whack. If your soil is balanced and you keep your tolerances really tight then I agree runoff pH has no value. I think we all agree that runoff PPM is vital.
I don't know if it's vital. It's a useful bit of information when dialing things in, especially when using low-nutrient soil, feeding more synthetic than organic nutrients. It helped me a lot.
Dr. Who
Well-Known Member
@orbo @az2000
Guys, this was not meant as a pissing match.....
In the very long time I have been doing this, I find (personally) NO use (anymore) to ppm in-going or run off....(in soil)
ALTHOUGH,,, I CAN respect the method you have mastered for your "tells" by run off ppm....az, I like your first post. You explained well!
In my experience, I used formulations from makers that actually had respect for their customers and kept their charts and formulations directed at cannabis and never really needed that kind of attention.....Back in the days of nothing but powdered formula's. (They still work and many here still use nothing but) I did adjust to max use by ppm relations. I have no use for synthetics any more so it's rather a moot point.
But not really "vital" is correct in my book too.
We gave alternate views on the topic and we are all correct!
In all my years I was never happy with any attempt to pH run off......while there are formula's and your correct they have way to many variables, It is FAR easier to (when using synthetics) simply pH all in-going to 6.5 and if you have Mg or P problems - 6.7 and look for reaction in the new growth....(be sure your soil is properly limed or "ph amended")
The bulk of the folks asking questions here are just starting out and 98% of them have read/know nothing about growing anything, much less canna. Therefor, I tend to speak in general and avoid advanced methods......I mean, come on....The questions you see here are the one's that have been repeated over and over and over.......KISS is a good starting place for the bulk of those asking them. I tend to be more "at" the problem when they say things like "3 years and the same problem" or the like as in # of grow runs...
No one really gave a "wrong" answer.....just one's I feel are a tick more advanced for the mass's here.
Peace on Bro's
Guys, this was not meant as a pissing match.....
In the very long time I have been doing this, I find (personally) NO use (anymore) to ppm in-going or run off....(in soil)
ALTHOUGH,,, I CAN respect the method you have mastered for your "tells" by run off ppm....az, I like your first post. You explained well!
In my experience, I used formulations from makers that actually had respect for their customers and kept their charts and formulations directed at cannabis and never really needed that kind of attention.....Back in the days of nothing but powdered formula's. (They still work and many here still use nothing but) I did adjust to max use by ppm relations. I have no use for synthetics any more so it's rather a moot point.
But not really "vital" is correct in my book too.
We gave alternate views on the topic and we are all correct!
In all my years I was never happy with any attempt to pH run off......while there are formula's and your correct they have way to many variables, It is FAR easier to (when using synthetics) simply pH all in-going to 6.5 and if you have Mg or P problems - 6.7 and look for reaction in the new growth....(be sure your soil is properly limed or "ph amended")
The bulk of the folks asking questions here are just starting out and 98% of them have read/know nothing about growing anything, much less canna. Therefor, I tend to speak in general and avoid advanced methods......I mean, come on....The questions you see here are the one's that have been repeated over and over and over.......KISS is a good starting place for the bulk of those asking them. I tend to be more "at" the problem when they say things like "3 years and the same problem" or the like as in # of grow runs...
No one really gave a "wrong" answer.....just one's I feel are a tick more advanced for the mass's here.
Peace on Bro's
outlier
Well-Known Member
@orbo is on the money with the 20% pot volume thing. Read that somewhere when I was researching hempy and it has served me well in my dtw coco, hempy and soil grows. Take your pot size, divide it by 5 and water that amount slowly and evenly like orbo also said.
This has been handy for me to prepare my water as I have to ph it down from over 10 this time of year. Count remaining pots, 20% of their volume is the minimum amount I'll need in water
This has been handy for me to prepare my water as I have to ph it down from over 10 this time of year. Count remaining pots, 20% of their volume is the minimum amount I'll need in water
orbo
Well-Known Member
All good Doc. IMO, the key to what you stated above is "(anymore)". Personally, I think all new growers should monitor everything they can monitor at their disposal until they get to a point where they can sit back and say.....anymore.
Vital was a poor choice of words. Probably telling would have been a better choice. (I stole that from Dr Who)
Littlebeezy
Member
So the consensus is what? Water until there's lots of runoff or water til soil is saturated?
It depends on the type of soil you use, the nutrients, the strength. Runoff is playing it safe if you use a soil without nutrients baked into it, and feed heavy. You could find a sweet spot of nutrient strength and not have to runoff. But, I like to feed a little heavier than that and "wipe the plate clean" (a little) with each feeding (via runoff).
Try it one way and the other. See what works best for you. (But, I would monitor runoff ppms so you can catch a problem before it shows in the leaves, if you overfeed without runoff.).
Try it one way and the other. See what works best for you. (But, I would monitor runoff ppms so you can catch a problem before it shows in the leaves, if you overfeed without runoff.).
Littlebeezy
Member
Buddha bloom 0.5-2-1. Watering every three days about 3/4 gallon per pot...just til i see runoff. feeding every other watering. Just starting 6th week of flower. Plants are showing signs of N tox...but I don't think that's what it is. Can't figure out what's wrong...leaves clawing/drooping, bud growth stunted.
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Littlebeezy
Member
I'll try and get some. There us no discoloration of any of the leaves...just clawing/drooping.